Not sure if the profile in comment 0 is still applicable? It seems a lot of time is spent in "http-on-before-connect" observers - matching WebExtension requests. I think this can stay P3 for now.
Bug 1565019 Comment 4 Edit History
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Not sure if the profile in comment 0 is still applicable? It seems a lot of time is spent in "http-on-before-connect" observers - matching WebExtension requests. I think this can stay S3 for now.